New Oregon wheat varieties promise yield, rust resistance

Two new Oregon State University soft white winter wheat varieties are being touted for their high yield potential and stripe rust resistance.

Wheat breeder Bob Zemetra said Bobtail and Rosalyn topped variety trials in Oregon and some in Washington.

Bobtail averaged 10 bushels more than the usual yield in higher rainfall and irrigated zones, according to Oregon trials. Zemetra said it does a little less than that in dryland areas. It has moderate resistance to strawbreaker footrot because it carries the PCH2 gene, the relatively new second gene for resistance. Most varieties carry the PCH1 gene.

"It's in a few varieties in the Northwest, but not very many," Zemetra said of the second gene. "It confers summer resistance to strawbreaker."

Bobtail is moderately resistant to cephalosporium stripe, but showed great tolerance for the disease in a Washington State University trial, Zemetra said. It has moderate resistance to septoria leaf blotch, of note to growers in Western Oregon, and excellent end-use quality.

Rosalyn topped Bobtail in moderate to high rainfall trials and drier zones. It has better adaptation to dry zones and good resistance to strawbreaker foot rot, carrying both the PCH1 and PCH2 genes. It is more susceptible to cephalosporium stripe and septoria leaf blotch.

As a wheat breeder, Zemetra worries about a possible change in stripe rust races affecting the area.

"What looks good today might look bad tomorrow," he said.

Both were higher yielding in Washington variety trials to WSU varieties Xerpha and Otto, Zemetra said. The OSU varieties are likely adapted to different environments.

The two varieties have short or no awns, the bristle of the wheat plant, rather than long awns, which may require farmers to adjust the settings on their combines at harvest to reduce the amount of chaff. Zemetra said.

The varieties combined Pacific Northwest germplasm and European germplasm. Most European wheats and varieties in the eastern United States are awnless, Zemetra said.

"If the awn gave that much of an advantage, we would probably see more awn wheat there," he said.

Bobtail gets its name from the awnless appearance, Zemetra said, comparing it to a bobtail cat. Rosalyn is named for the mother of an OSU technician, who was popular in the community and died last year.

Zemetra said there was discussion between OSU and the Oregon Wheat Commission whether to move ahead with royalties on wheat varieties. It was decided that there needs to be a consensus moving forward, so Bobtail and Rosalyn will have a traditional release with no royalties attached.

Foundation seed for Bobtail is being produced through the Washington State Crop Improvement Association, but may all be spoken for. Zemetra reselected Rosalyn for test weight, so there will be a limited amount of foundation seed available in the fall. Zemetra said farmers will likely get more Bobtail in the fall of 2014 and Rosalyn on a limited basis.

Zemetra said he will next pursue wheats adapted to drier areas and focus on resistance to soilborne wheat mosaic virus. He is also close to finding the right combination of yield, stripe rust resistance and end-use quality for a hard white wheat. The challenge will be preventing intermingling with soft white wheat, he said.